Preliminaries

transition_states()

transition_states() works with discrete data.

Goal: We want to create an animate figure which shows the Petal.Length and Petal.Width of the iris data set.

The first step to create an animated figure is to creat the static ggplot image. This will contain “all” the data to be plotted and will not look the same as the animated figure.

Load data

I like to build my plots step-by-step, so I save them as objects once I get them looking as I want.

Adding colors will force the plot to be “choppy.”

animated plot

With the static plot made, let’s add some animation with the transition_states() function. The user must declare the state to transition among.

iris_anim <- iris_plot + 
  transition_states(Species)
iris_anim

Four arguments

transition_states() takes four arguments:

  • states - variable name that contains discrete data
  • transition_length - The relative length of the transition (default = 1)
  • state_length - the relative length of the pause between states (default = 1)
  • wrap - Should the animate wrap around? (default = TRUE) If TRUE the last state will be transitioned into the first.

transition_states(states, transition_length, state_length, wrap = TRUE)

These transitions look a bit slow. We have considerable power to fine-tune the speed of the transitions.

iris_anim <-  iris_plot +
  transition_states(Species,
                    transition_length = 2, 
                    state_length = 1)
iris_anim